The present invention is directed to various formulations of taxane derivatives having improved solubility as compared to paclitaxel, particularly formulations of such taxane derivatives for parenteral administration to a patient.
Paclitaxel has shown remarkable antineoplastic effect in a wide range of human cancers. Initially approved in 1992 for the treatment of refractory ovarian cancer, paclitaxel is now the first-line therapy for metastatic breast cancer and advanced ovarian cancer. Paclitaxel""s effectiveness has also been demonstrated against non-small cell lung cancer, head and neck cancers, melanoma, colon cancer and Kaposi""s sarcoma. In addition to its cytotoxic effects, paclitaxel has also been shown to be a potent inhibitor of angiogenesis. Despite its broad clinical utility, there has been difficulty formulating paclitaxel because of its insolubility in water. The aqueous solubility of paclitaxel is only 0.25 g per ml. Paclitaxel is also insoluble in most pharmaceutically-acceptable solvents, and lacks a suitable chemical functionality for formation of a more soluble salt. Consequently, special formulations are required for parenteral administration of paclitaxel. Paclitaxel is very poorly absorbed when administered orally (less than 1%). No oral formulation of paclitaxel has obtained regulatory approval for administration to patients.
Paclitaxel is currently formulated as Taxol(copyright), which is a concentrated nonaqueous solution containing 6 mg paclitaxel per ml in a vehicle composed of 527 mg of polyoxyethylated castor oil (Cremophor(copyright) EL) and 49.7% (v/v) dehydrated ethyl alcohol, USP, per milliliter (available from Bristol-Myers Squibb Co., Princeton, N.J.). Cremophor(copyright) EL improves the physical stability of the solution, and ethyl alcohol solubilizes paclitaxel. The solution is stored under refrigeration and diluted just before use in 5% dextrose or 0.9% saline. Intravenous infusions of paclitaxel are generally prepared for patient administration within the concentration range of 0.3 to 1.2 mg/ml. In addition to paclitaxel, the diluted solution for administration consists of up to 10% ethanol, up to 10% Cremophor(copyright) EL and up to 80% aqueous solution. However, dilution to certain concentrations may produce a supersaturated solution that could precipitate. An inline 0.22 micron filter is used during Taxol(copyright) administration to guard against the potentially life-threatening infusion of particulates.
Several toxic side effects have resulted from the administration of paclitaxel in a Cremophor(copyright)/ethanol-based formulation including anaphylactic reactions, hypotension, angioedema, urticaria, peripheral neuropathy, arthralgia, mucositis, nausea, vomiting, alopecia, alcohol poisoning, respiratory distress such as dyspnea, cardiovascular irregularities, flu-like symptoms such as myalgia, gastrointestinal distress, hematologic complications such as neutropenia, genitourinary effects, and skin rashes. Some of these undesirable adverse effects were encountered in clinical trials, and in at least one case, the reaction was fatal. To reduce the incidence and severity of these reactions, patients are premedicated with corticosteroids, diphenhydramine, H2-antagonists, antihistamines, or granulocyte colony-stimulating factor (G-CSF), and the duration of the infusion has been prolonged. Although such premedication has reduced the incidence of serious hypersensitivity reactions to less than 5%, milder reactions are still reported in approximately 30% of patients.
There is an additional drawback to the Cremophor(copyright)-based formulation. Cremophor(copyright) EL can leach phthalate plasticizers from polyvinyl chloride infusion bags and intravenous administration set tubing. This has led to the use of glass bottles or polyolefin containers for storing Taxol(copyright) solution and polyethylene-lined administration tubing or tubing made with tris (2-ethylhexyl) trimellitate plasticizer for Taxol(copyright) administration.
The physiological problems associated with paclitaxel administration have limited the dosage of paclitaxel that a patient can receive and prolonged the time of administration. Paclitaxel is typically given in a dose ranging from about 110 mg/m2 to 300 mg/m2 over a 3-24 hour period every 21 days or more, often with premedication. At dosages above 300 mg/m2, peripheral neuropathy has been observed. Infusion times do not generally exceed 24 hours because the paclitaxel is physically stable for only 27 hours.
In instances where a patient receives a multi-day continuous infusion, the patient must have a new bag of Taxol(copyright) solution each day. In addition to the inconvenience for patients and staff and increased therapy cost, the bag exchange increases the risk of intravenous catheter microbial colonization. It would be advantageous to have a taxane product that remains stable for the entire period of the multi-day administration.
There is a strong need for reformulating taxane compositions using a safer and better-tolerated vehicle than Cremophor(copyright). Alternative formulations of paclitaxel that avoid the use of Cremophor(copyright) have been proposed. One approach is incorporation of the drug into a liposomal formulation. However, it has been reported that there is difficulty in achieving a quantitative incorporation of the drug into the liposomal compartment, and that low loading capability and nonspecific uptake by the reticuloendothelial system have limited the clinical usefulness of such liposomes. This formulation is also not storage stable and must be freeze dried and reconstituted before use.
Another approach is to formulate paclitaxel as a lipid emulsion. Most of the efforts to create a paclitaxel formulation as a stable lipid emulsion have been unsuccessful. It has been widely reported in the literature that paclitaxel is insoluble in lipid emulsions containing soybean oil, such as Intralipid(copyright), or lipid emulsions that are a mixture of soybean and safflower oils, such as Liposyn(copyright). See, for example, L. C. Collins-Gold et al., xe2x80x9cParenteral Emulsions for Drug Delivery,xe2x80x9d Advanced Drug Delivery Reviews, 5, 189-208 (1990); B. D. Tarr, xe2x80x9cA New Parenteral Emulsion for the Administration of Taxol,xe2x80x9d Pharmaceutical Research, 4(2), 163 (1987); Dolatrai M. Vyas, Paclitaxel (Taxol) Formulation And Prodrugs, The Chemistry and Pharmacology of Taxol and its Derivatives, Elsevier Science B. V., 107 (1995); J. M. Meerum Terwogt et al., xe2x80x9cAlternative Formulations of Paclitaxelxe2x80x9d Cancer Treatment Reviews, 23, 89 (1997). Paclitaxel""s solubility in soybean oil is only 0.3 mg/ml. Vyas, supra. Physical methods for solubilizing paclitaxel in either soybean oil or safflower oil, such as heating or heating with sonication do not solubilize appreciable amounts of paclitaxel. Thus, the lipid emulsion formulations have significant drawbacks in that additives are still needed to solubilize paclitaxel and to prevent it from precipitating out of solution.
Tarr et al., supra, developed a parenteral triacetin emulsion formulation of paclitaxel. The emulsion contained 50% triacetin, 2.0% ethyl oleate, 1.5% Pluronic(copyright) F68, 1.5% purified soybean oil and 10 mg paclitaxel. Glycerol was added up to 10% to prevent creaming. This emulsion was reported to be adequately stable for parenteral administration. However, triacetin (glyceryl triacetate) itself proved to be toxic to mice when administered intravenously in concentrations required to deliver therapeutic doses of paclitaxel. Furthermore, no antitumor activity was observed with this formulation.
Andersson, U.S. Pat. No. 5,877,205, discloses a pharmaceutical composition for parenteral administration containing a taxane analog, dimethylacetamide, polyethylene glycol and an aqueous lipid emulsion. The aqueous lipid emulsion is preferably a soybean oil emulsion. Andersson solubilizes paclitaxel by dissolving it in an organic solvent of dimethylacetamide as the primary vehicle and adding a secondary polyethylene glycol solvent to stabilize the drug in solution for subsequent final dilution in an aqueous solvent, such as an aqueous lipid emulsion (e.g., emulsified soybean oil (Intralipid(copyright)), Liposyn(copyright), Soyacal(copyright), and Travemulsion(copyright)).
Kaufman et al., U.S. Pat. No. 5,616,330 report a composition of a taxine in a stable oil-in-water emulsion for intravenous administration. The taxine is dissolved in an alcohol and then mixed with an oil such as safflower or sunflower oil to form a solution. The alcohol is then removed from the solution by evaporation. The solution is added to an aqueous surfactant dispersion and stirred at high speed to form an emulsion. The emulsion is then refined through a homogenizer.
Although Taxol(copyright) and Taxotere(copyright) are useful chemotherapeutic formulations, there are limitations on their effectiveness, including limited efficacy against certain types of cancers and toxicity to subjects when administered at various doses. Accordingly, a need remains for additional formulations of chemotherapeutic agents with improved efficacy and less toxicity.
Among the various aspects of the present invention, therefore, is the provision of taxane-containing pharmaceutical compositions which compare favorably to Taxol(copyright) and Taxotere(copyright) formulations with respect to efficacy as anti-tumor agents and with respect to toxicity and stability.
Accordingly, it is an aspect of the invention to provide pharmaceutical compositions for oral or parenteral administration which comprise a taxane and at least one nonaqueous, pharmaceutically acceptable solvent. In one embodiment of the invention, the taxane has a solubility in ethanol of at least 100 mg/ml. In another aspect of the present invention, the taxane has a solubility in ethanol of at least 100 mg/ml and is capable of being crystallized from a solution. In yet another aspect, the pharmaceutical compositions comprise a taxane which has a solubility in ethanol of at least 60 mg/ml and an ID50 value determined relative to the HCT116 cell line that is at least 4 times less than that of paclitaxel.
A further aspect of the present invention is the provision of pharmaceutical compositions for oral or parenteral administration which comprise a taxane of the invention and a pharmaceutically acceptable carrier.
Other objects and features of this invention will be in part apparent and in part pointed out hereinafter.
The present invention provides compositions and methods for the solubilization of taxane antitumor compounds in pharmaceutically acceptable carriers. The taxanes of the invention are more soluble in the carriers and exhibit greater cytotoxic activity as compared to paclitaxel. Therefore, taxane compositions can be formulated to include significantly less ethanol and Cremophor(copyright) EL solution as compared to Taxol(copyright) solution, or can be formulated to be free of ethanol and/or Cremophor(copyright) solution. The taxanes remain physically and chemically stable in the compositions for an extended period of time, allowing for multi-day continuous infusion without replacement of the composition and for administration without the use of an inline filter. The taxane compositions can be administered systemically or locally without undue toxicity caused by the carrier or by precipitation or recrystallization of the taxane. The risk of anaphylactic reactions or other adverse side effects is minimized with the compositions of the invention.
The compositions of the invention allow for a broad range of administration protocols including oral administration. Oral administration has been found to decrease toxic side effects as compared with conventional intraveneous therapy. Rather than producing a sudden high taxane concentration in blood levels as is usually the case with an intravenous infusion, absorption of the taxane through the gut wall provides a more gradual appearance of taxane in the blood levels and enables a stable, steady-state maintenance of desired levels for a long period of time. The compositions can also be administered parenterally in less than 1, 2 or 3 hours so that patients can be treated on an out-patient basis while still providing an anti-neoplastic effective dosage without exceeding dose-limiting toxicities. The compositions are also effective in minimizing or eliminating premedication to reduce patient discomfort and the expense and duration of treatment. In instances where parenteral administration cannot be shortened in duration, the compositions contain lower taxane concentrations as compared to conventional paclitaxel compositions and result in minimal or no adverse side effects.
In one embodiment of the present invention, the taxanes of the present invention correspond to structure (1): 
wherein
one of R7 and R10 is hydroxy and the other is acyloxy;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, phenyl or heterocyclo;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10;
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo;
R2 is acyloxy;
R9 is keto, hydroxy, or acyloxy;
R14 is hydrido or hydroxy; and
Ac is acetyl.
R7, R9, and R10 independently have the alpha or beta stereochemical configuration.
In one embodiment, R2 is an ester (R2aC(O)Oxe2x80x94), a carbamate (R2aR2bNC(O)Oxe2x80x94), a carbonate (R2aOC(O)Oxe2x80x94), or a thiocarbamate (R2aSC(O)Oxe2x80x94) wherein R2a and R2b are independently hydrogen, hydrocarbyl, substituted hydrocarbyl or heterocyclo. In a preferred embodiment, R2 is an ester (R2aC(O)Oxe2x80x94), wherein R2a is aryl or heteroaromatic. In another preferred embodiment, R2 is an ester (R2aC(O)Oxe2x80x94), wherein R2a is substituted or unsubstituted phenyl, furyl, thienyl, or pyridyl. In one particularly preferred embodiment, R2 is benzoyloxy.
While R9 is keto in one embodiment of the present invention, in other embodiments R9 may have the alpha or beta stereochemical configuration, preferably the beta stereochemical configuration, and may be, for example, xcex1- or xcex2-hydroxy or xcex1- or xcex2-acyloxy. For example, when R9 is acyloxy, it may be an ester (R9aC(O)Oxe2x80x94), a carbamate (R9aR9bNC(O)Oxe2x80x94), a carbonate (R9aOC(O)Oxe2x80x94), or a thiocarbamate (R9aSC(O)Oxe2x80x94) wherein R9a and R9b are independently hydrogen, hydrocarbyl, substituted hydrocarbyl or heterocyclo. If R9 is an ester (R9aC(O)Oxe2x80x94), R9a is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted aryl or substituted or unsubstituted heteroaromatic. Still more preferably, R9 is an ester (R9aC(O)Oxe2x80x94), wherein R9a is substituted or unsubstituted phenyl, substituted or unsubstituted furyl, substituted or unsubstituted thienyl, or substituted or unsubstituted pyridyl. In one embodiment R9 is (R9aC(O)Oxe2x80x94) wherein R9a is methyl, ethyl, propyl (straight, branched or cyclic), butyl (straight, branched or cyclic), pentyl, (straight, branched or cyclic), or hexyl (straight, branched or cyclic). In another embodiment R9 is (R9aC(O)Oxe2x80x94) wherein R9a is substituted methyl, substituted ethyl, substituted propyl (straight, branched or cyclic), substituted butyl (straight, branched or cyclic), substituted pentyl, (straight, branched or cyclic), or substituted hexyl (straight, branched or cyclic) wherein the substituent(s) is/are selected from the group consisting of heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, keto, acyloxy, nitro, amino, amido, thiol, ketal, acetal, ester and ether moieties, but not phosphorous containing moieties.
Exemplary X3 substituents include substituted or unsubstituted C2 to C8 alkyl, substituted or unsubstituted C2 to C8 alkenyl, substituted or unsubstituted C2 to C8 alkynyl, substituted or unsubstituted heteroaromatics containing 5 or 6 ring atoms, and substituted or unsubstituted phenyl. Exemplary preferred X3 substituents include substituted or unsubstituted ethyl, propyl, butyl, cyclopropyl, cyclobutyl, cyclohexyl, isobutenyl, furyl, thienyl, and pyridyl.
Exemplary X5 substituents include xe2x80x94COX10, xe2x80x94COOX10 or xe2x80x94CONHX10 wherein X10 is substituted or unsubstituted alkyl, alkenyl, phenyl or heteroaromatic. Exemplary preferred X5 substituents include xe2x80x94COX10, xe2x80x94COOX10 or xe2x80x94CONHX10 wherein X10 is (i) substituted or unsubstituted C1 to C8 alkyl such as substituted or unsubstituted methyl, ethyl, propyl (straight, branched or cyclic), butyl (straight, branched or cyclic), pentyl (straight, branched or cyclic), or hexyl (straight, branched or cyclic); (ii) substituted or unsubstituted C2 to C8 alkenyl such as substituted or unsubstituted ethenyl, propenyl (straight, branched or cyclic), butenyl (straight, branched or cyclic), pentenyl (straight, branched or cyclic) or hexenyl (straight, branched or cyclic); (iii) substituted or unsubstituted C2 to C8 alkynyl such as substituted or unsubstituted ethynyl, propynyl (straight or branched), butynyl (straight or branched), pentynyl (straight or branched), or hexynyl (straight or branched); (iv) substituted or unsubstituted phenyl, or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl, wherein the substituent(s) is/are selected from the group consisting of heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, keto, acyloxy, nitro, amino, amido, thiol, ketal, acetal, ester and ether moieties, but not phosphorous containing moieties.
C10 Carbonates
In one embodiment, R10 is R10aOCOOxe2x80x94 wherein R10a is (i) substituted or unsubstituted C1 to C8 alkyl (straight, branched or cyclic), such as methyl, ethyl, propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl (straight, branched or cyclic), such as ethenyl, propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl (straight or branched) such as ethynyl, propynyl, butynyl, pentynyl, or hexynyl; (iv) substituted or unsubstituted phenyl; or (v) substituted or unsubstituted heterocyclo such as furyl, thienyl, or pyridyl. The substituents may be hydrocarbyl or any of the heteroatom containing substituents identified elsewhere herein for substituted hydrocarbyl. In a preferred embodiment, R10a is methyl, ethyl, straight, branched or cyclic propyl, straight, branched or cyclic butyl, straight, branched or cyclic hexyl, straight or branched propenyl, isobutenyl, furyl or thienyl. In another embodiment, R10a is substituted ethyl, substituted propyl (straight, branched or cyclic), substituted propenyl (straight or branched), substituted isobutenyl, substituted furyl or substituted thienyl wherein the substituent(s) is/are selected from the group consisting of heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, keto, acyloxy, nitro, amino, amido, thiol, ketal, acetal, ester and ether moieties, but not phosphorous containing moieties.
In one of the preferred embodiments, the taxanes of the present invention correspond to structure (2): 
wherein
R7 is hydroxy;
R10 is carbonate;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, or heterocyclo, wherein alkyl comprises at least two carbon atoms;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10; and
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
For example, in this preferred embodiment in which the taxane corresponds to structure (2), R10 may be R10aOCOOxe2x80x94 wherein R10a is substituted or unsubstituted methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably substituted or unsubstituted methyl, ethyl or propyl, still more preferably substituted or unsubstituted methyl, ethyl, and still more preferably unsubstituted methyl or ethyl. While R7a is selected from among these, in one embodiment X3 is selected from substituted or unsubstituted alkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted alkenyl, phenyl or heterocyclo, still more preferably substituted or unsubstituted phenyl or heterocyclo, and still more preferably heterocyclo such as furyl, thienyl or pyridyl. While R10a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl. Alternatively, while R10a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl, or X5 is xe2x80x94COOX10 wherein X10 is alkyl, preferably t-butyl. Among the more preferred embodiments, therefore, are taxanes corresponding to structure (2) in which (i) X5 is xe2x80x94COOX10 wherein X10 is tert-butyl or X5 is xe2x80x94COX10 wherein X10 is phenyl, (ii) X3 is substituted or unsubstituted cycloalkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted isobutenyl, phenyl, furyl, thienyl, or pyridyl, still more preferably unsubstituted isobutenyl, furyl, thienyl or pyridyl, and (iii) R10a is unsubstituted methyl, ethyl or propyl, more preferably methyl or ethyl.
Among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R10 is R10aOCOOxe2x80x94 wherein R10a is methyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
Also among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R10a is R10OCOOxe2x80x94 wherein R10a is ethyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
Also among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R10 is R10aOCOOxe2x80x94 wherein R10a is propyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
C10 Esters
In one embodiment, R10 is R10aCOOxe2x80x94 wherein R10a is (i) substituted or unsubstituted C2 to C8 alkyl (straight, branched or cyclic), such as ethyl, propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl (straight, branched or cyclic), such as ethenyl, propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl (straight or branched) such as ethynyl, propynyl, butynyl, pentynyl, or hexynyl; (iv) substituted or unsubstituted phenyl; or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl. The substituents may be hydrocarbyl or any of the heteroatom containing substituents identified elsewhere herein for substituted hydrocarbyl. In a preferred embodiment, R10a is ethyl, straight, branched or cyclic propyl, straight, branched or cyclic butyl, straight, branched or cyclic pentyl, straight, branched or cyclic hexyl, straight or branched propenyl, isobutenyl, furyl or thienyl. In another embodiment, R10a is substituted ethyl, substituted propyl (straight, branched or cyclic), substituted propenyl (straight or branched), substituted isobutenyl, substituted furyl or substituted thienyl wherein the substituent(s) is/are selected from the group consisting of heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, keto, acyloxy, nitro, amino, amido, thiol, ketal, acetal, ester and ether moieties, but not phosphorous containing moieties.
In one of the preferred embodiments, the taxanes of the present invention correspond to structure (2): 
wherein
R7 is hydroxy;
R10 is R10aCOOxe2x80x94;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, or heterocyclo, wherein alkyl comprises at least two carbon atoms;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10; and
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo; and
R10a, is hydrocarbyl, substituted hydrocarbyl, or heterocyclo wherein said hydrocarbyl or substituted hydrocarbyl contains carbon atoms in the alpha and beta positions relative to the carbon of which R10a is a substituent;
Bz is benzoyl; and
Ac is acetyl.
For example, in this preferred embodiment in which the taxane corresponds to the above structure (2), R10a may be substituted or unsubstituted ethyl, propyl or butyl, more preferably substituted or unsubstituted ethyl or propyl, still more preferably substituted or unsubstituted ethyl, and still more preferably unsubstituted ethyl. While R10a is selected from among these, in one embodiment X3 is selected from substituted or unsubstituted alkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted alkenyl, phenyl or heterocyclo, still more preferably substituted or unsubstituted phenyl or heterocyclo, and still more preferably heterocyclo such as furyl, thienyl or pyridyl. While R10a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl. Alternatively, while R10a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl, or X5 is xe2x80x94COOX10 wherein X10 is alkyl, preferably t-butyl. Among the more preferred embodiments, therefore, are taxanes corresponding to structure (2) in which (i) X5 is xe2x80x94COOX10 wherein X10 is tert-butyl or X5 is xe2x80x94COX10 wherein X10 is phenyl, (ii) X3 is substituted or unsubstituted cycloalkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted isobutenyl, phenyl, furyl, thienyl, or pyridyl, still more preferably unsubstituted isobutenyl, furyl, thienyl or pyridyl, and (iii) R7a is unsubstituted ethyl or propyl, more preferably ethyl.
Among the preferred embodiments, therefore, are taxanes corresponding to structure 1 or 2 wherein R10 is R10aCOOxe2x80x94 wherein R10a is ethyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
Also among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R10 is R10aCOOxe2x80x94 wherein R10a is propyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
C10 Carbamates
In one embodiment, R10 is R10aR10bNCOOxe2x80x94 wherein R10a and R10b are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo. Exemplary preferred R10 substituents include R10aR10bNCOOxe2x80x94 wherein (a) R10a and R10a are each hydrogen, (b) one of R10a and R10b is hydrogen and the other is (i) substituted or unsubstituted C1 to C8 alkyl such as methyl, ethyl, or straight, branched or cyclic propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl such as ethenyl or straight, branched or cyclic propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl such as ethynyl or straight or branched propynyl, butynyl, pentynyl, or hexynyl; (iv) substituted or unsubstituted phenyl, or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl, or (c) R10a and R10b are independently (i) substituted or unsubstituted C1 to C8 alkyl such as methyl, ethyl, or straight, branched or cyclic propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl such as ethenyl or straight, branched or cyclic propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl such as ethynyl or straight or branched propynyl, butynyl, pentynyl, or hexynyl; (iv) substituted or unsubstituted phenyl, or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl. The substituents may be those identified elsewhere herein for substituted hydrocarbyl. In one embodiment, preferred R10 substituents include R10aR10bNCOOxe2x80x94 wherein one of R10a and R10b is hydrogen and the other is methyl, ethyl, or straight, branched or cyclic propyl.
In one of the preferred embodiments, the taxanes of the present invention correspond to structure (2): 
wherein
R7 is hydroxy;
R10 is carbamoyloxy;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, or heterocyclo, wherein alkyl comprises at least two carbon atoms;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10; and
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
For example, in this preferred embodiment in which the taxane corresponds to structure (2), R10 may be R10aR10bNCOOxe2x80x94 wherein one of R10a and R10b is hydrogen and the other is (i) substituted or unsubstituted C1 to C8 alkyl such as methyl, ethyl, or straight, branched or cyclic propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl such as ethenyl or straight, branched or cyclic propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl such as ethynyl or straight or branched propynyl, butynyl, pentynyl, or hexynyl; (iv) phenyl or substituted phenyl such as nitro, alkoxy or halosubstituted phenyl, or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl. The substituents may be those identified elsewhere herein for substituted hydrocarbyl. In one embodiment, preferred R10 substituents include R10aR10bNCOOxe2x80x94 wherein one of R10a and R10b is hydrogen and the other is substituted or unsubstituted, preferably unsubstituted methyl, ethyl, or straight, branched or cyclic propyl. In another embodiment, preferred R10 substituents include R10aR10bNCOOxe2x80x94 wherein one of R10a and R10b is hydrogen and the other is substituted or unsubstituted phenyl or heterocyclo. While R10a and R10b are selected from among these, in one embodiment X3 is selected from substituted or unsubstituted alkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted alkenyl, phenyl or heterocyclo, still more preferably substituted or unsubstituted phenyl or heterocyclo, and still more preferably heterocyclo such as furyl, thienyl or pyridyl. While R10a, R10b, and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl. Alternatively, while R10a, R10b, and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl, or X5 is xe2x80x94COOX10 wherein X10 is alkyl, preferably t-butyl. Among the more preferred embodiments, therefore, are taxanes corresponding to structure (2) in which (i) X5 is xe2x80x94COOX10 wherein X10 is tert-butyl or X5 is xe2x80x94COX10 wherein X10 is phenyl, (ii) X3 is substituted or unsubstituted cycloalkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted isobutenyl, phenyl, furyl, thienyl, or pyridyl, still more preferably unsubstituted isobutenyl, furyl, thienyl or pyridyl, and (iii) R10 is R10aR10bNCOOxe2x80x94, one of R10a and R10b is hydrogen and the other is substituted or unsubstituted substituted or unsubstituted C1 to C8 alkyl, phenyl or heterocyclo.
Among the preferred embodiments, therefore, are taxanes corresponding to structure 1 or 2 wherein R10 is R10aR10bNCOOxe2x80x94 wherein R10a is methyl and R10b is hydrido. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
Also among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R10 is R10aR10bNCOOxe2x80x94 wherein R10a is ethyl and R10b is hydrido. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
C10 Heterosubstituted Acetates
In one embodiment, R10 is R10aC(O)Oxe2x80x94 wherein R10a is heterosubstituted methyl, said heterosubstituted methyl moiety lacking a carbon atom which is in the beta position relative to the carbon atom of which R10a is a substituent. The heterosubstituted methyl is covalently bonded to at least one heteroatom and optionally with hydrogen, the heteroatom being, for example, a nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or halogen atom. The heteroatom may, in turn, be substituted with other atoms to form a heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, oxy, acyloxy, nitro, amino, amido, thiol, ketals, acetals, esters or ether moiety. Exemplary R10 substituents include R10aCOOxe2x80x94 wherein R10a is chloromethyl, hydroxymethyl, methoxymethyl, ethoxymethyl, acetoxymethyl, acyloxymethyl, or methylthiomethyl.
In one of the preferred embodiments, the taxane corresponds to structure 1, X5 is xe2x80x94COX10 wherein X10 is phenyl or xe2x80x94COOX10 wherein X10 is t-butoxycarbonyl, and R10 is R10aC(O)Oxe2x80x94 wherein R10a is alkoxymethyl, preferably methoxymethyl or ethoxymethyl. In another embodiment of the present invention the taxane corresponds to structure 1, X5 is xe2x80x94COX10 wherein X10 is phenyl or xe2x80x94COOX10 wherein X10 is t-butoxycarbonyl, and R10 is R10aC(O)Oxe2x80x94 wherein R10a is acyloxymethyl, preferably acetoxymethyl.
In another embodiment of the present invention, the taxane corresponds to structure 1, X5 is xe2x80x94COX10 wherein X10 is phenyl or xe2x80x94COOX10 wherein X10 is t-butoxycarbonyl, R10 is R10aC(O)Oxe2x80x94 wherein R10a is alkoxymethyl such as methoxymethyl or ethoxymethyl, or aryloxymethyl such as phenoxymethyl, and X3 is heterocyclo. In another embodiment of the present invention the taxane corresponds to structure 1, X5 is xe2x80x94COX10 wherein X10 is phenyl or xe2x80x94COOX10 wherein X10 is t-butoxycarbonyl, and R10 is R10aC(O)Oxe2x80x94 wherein R10a is acyloxymethyl, preferably acetoxymethyl, and X3 is heterocyclo.
In another embodiment, the taxanes correspond to structure (2): 
wherein
R7 is hydroxy;
R10 is heterosubstituted acetate;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, or heterocyclo, wherein alkyl comprises at least two carbon atoms;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10; and
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
For example, in this preferred embodiment in which the taxane corresponds to structure (2), R10 is R10aCOOxe2x80x94 wherein R10a is heterosubstituted methyl, more preferably heterosubstituted methyl wherein the heterosubsituents are selected from the group consisting of nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or halogen atoms, still more preferably heterosubstituted methyl wherein the heterosubstituent is alkoxy or acyloxy. While R10a is selected from among these, in one embodiment X3 is selected from substituted or unsubstituted alkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted alkenyl, phenyl or heterocyclo, still more preferably substituted or unsubstituted phenyl or heterocyclo, and still more preferably heterocyclo such as furyl, thienyl or pyridyl. While R10a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl. Alternatively, while R10a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl, or X5 is xe2x80x94COOX10 wherein X10 is alkyl, preferably t-butyl. Among the more preferred embodiments, therefore, are taxanes corresponding to structure (2) in which (i) X5 is xe2x80x94COOX10 wherein X10 is tert-butyl or X5 is xe2x80x94COX10 wherein X10 is phenyl, (ii) X3 is substituted or unsubstituted cycloalkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted isobutenyl, phenyl, furyl, thienyl, or pyridyl, still more preferably unsubstituted isobutenyl, furyl, thienyl or pyridyl, and (iii) R10 is alkoxyacetyl aryloxyacetyl, or acyloxyacetyl.
C7 Carbonates
In one embodiment, R7 is R7aOCOOxe2x80x94 wherein R7a is (i) substituted or unsubstituted C1 to C8 alkyl (straight, branched or cyclic), such as methyl, ethyl, propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl (straight, branched or cyclic), such as ethenyl, propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl (straight or branched) such as ethynyl, propynyl, butynyl, pentynyl, or hexynyl; (iv) substituted or unsubstituted phenyl; or (v) substituted or unsubstituted heterocyclo such as furyl, thienyl, or pyridyl. The substituents may be hydrocarbyl or any of the heteroatom containing substituents identified elsewhere herein for substituted hydrocarbyl. In a preferred embodiment, R7a is methyl, ethyl, straight, branched or cyclic propyl, straight, branched or cyclic butyl, straight, branched or cyclic hexyl, straight or branched propenyl, isobutenyl, furyl or thienyl. In another embodiment, R7a is substituted ethyl, substituted propyl (straight, branched or cyclic), substituted propenyl (straight or branched), substituted isobutenyl, substituted furyl or substituted thienyl wherein the substituent(s) is/are selected from the group consisting of heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, keto, acyloxy, nitro, amino, amido, thiol, ketal, acetal, ester and ether moieties, but not phosphorous containing moieties.
In one of the preferred embodiments, the taxanes of the present invention correspond to structure (2): 
wherein
R7 is carbonate;
R10 is hydroxy;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, or heterocyclo, wherein alkyl comprises at least two carbon atoms;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10; and
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
For example, in this preferred embodiment in which the taxane corresponds to structure (2), R7 may be R7aOCOOxe2x80x94 wherein R7a is substituted or unsubstituted methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably substituted or unsubstituted methyl, ethyl or propyl, still more preferably substituted or unsubstituted methyl, ethyl, and still more preferably unsubstituted methyl or ethyl. While R7a is selected from among these, in one embodiment X3 is selected from substituted or unsubstituted alkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted alkenyl, phenyl or heterocyclo, still more preferably substituted or unsubstituted phenyl or heterocyclo, and still more preferably heterocyclo such as furyl, thienyl or pyridyl. While R7a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl. Alternatively, while R7a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl, or X5 is xe2x80x94COOX10 wherein X10 is alkyl, preferably t-butyl. Among the more preferred embodiments, therefore, are taxanes corresponding to structure (2) in which (i) X5 is xe2x80x94COOX10 wherein X10 is tert-butyl or X5 is xe2x80x94COX10 wherein X10 is phenyl, (ii) X3 is substituted or unsubstituted cycloalkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted isobutenyl, phenyl, furyl, thienyl, or pyridyl, still more preferably unsubstituted isobutenyl, furyl, thienyl or pyridyl, and (iii) R7a is unsubstituted methyl, ethyl or propyl, more preferably methyl or ethyl.
Among the preferred embodiments, therefore, are taxanes corresponding to structure 1 or 2 wherein R7 is R7aOCOOxe2x80x94 wherein R7a is methyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
Also among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R7 is R7aOCOOxe2x80x94 wherein R7a is ethyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
Also among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R7 is R7aOCOOxe2x80x94 wherein R7a is propyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
C7 Ester
In one embodiment, R7 is R7aCOOxe2x80x94 wherein R7a is (i) substituted or unsubstituted C2 to C8 alkyl (straight, branched or cyclic), such as ethyl, propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl (straight, branched or cyclic), such as ethenyl, propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl (straight or branched) such as ethynyl, propynyl, butynyl, pentynyl, or hexynyl; (iv) substituted or unsubstituted phenyl; or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl. The substituents may be hydrocarbyl or any of the heteroatom containing substituents identified elsewhere herein for substituted hydrocarbyl. In a preferred embodiment, R7a is ethyl, straight, branched or cyclic propyl, straight, branched or cyclic butyl, straight, branched or cyclic pentyl, straight, branched or cyclic hexyl, straight or branched propenyl, isobutenyl, furyl or thienyl. In another embodiment, R7a is substituted ethyl, substituted propyl (straight, branched or cyclic), substituted propenyl (straight or branched), substituted isobutenyl, substituted furyl or substituted thienyl wherein the substituent(s) is/are selected from the group consisting of heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, keto, acyloxy, nitro, amino, amido, thiol, ketal, acetal, ester and ether moieties, but not phosphorous containing moieties.
In one of the preferred embodiments, the taxanes of the present invention correspond to the following structural formula (2): 
wherein
R7 is R7aCOOxe2x80x94;
R10 is hydroxy;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, or heterocyclo;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10;
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo;
R7a is hydrocarbyl, substituted hydrocarbyl, or heterocyclo wherein said hydrocarbyl or substituted hydrocarbyl contains carbon atoms in the alpha and beta positions relative to the carbon of which Ra is a substituent;
Bz is benzoyl; and
Ac is acetyl.
For example, in this preferred embodiment in which the taxane corresponds to structure (2), R7a may be substituted or unsubstituted ethyl, propyl or butyl, more preferably substituted or unsubstituted ethyl or propyl, still more preferably substituted or unsubstituted ethyl, and still more preferably unsubstituted ethyl. While R7a is selected from among these, in one embodiment X3 is selected from substituted or unsubstituted alkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted alkenyl, phenyl or heterocyclo, still more preferably substituted or unsubstituted phenyl or heterocyclo, and still more preferably heterocyclo such as furyl, thienyl or pyridyl. While R7a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl. Alternatively, while R7a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl, or X5 is xe2x80x94COOX10 wherein X10 is alkyl, preferably t-butyl. Among the more preferred embodiments, therefore, are taxanes corresponding to structure (2) in which (i) X5 is xe2x80x94COOX10 wherein X10 is tert-butyl or X5 is xe2x80x94COX10 wherein X10 is phenyl, (ii) X3 is substituted or unsubstituted cycloalkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted isobutenyl, phenyl, furyl, thienyl, or pyridyl, still more preferably unsubstituted isobutenyl, furyl, thienyl or pyridyl, and (iii) R7a is unsubstituted ethyl or propyl, more preferably ethyl.
Among the preferred embodiments, therefore, are taxanes corresponding to structure 1 or 2 wherein R7 is R7aCOOxe2x80x94 wherein R7a is ethyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
Also among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R7 is R7aCOOxe2x80x94 wherein R7a is propyl. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
C7 Carbamates
In one embodiment, R7 is R7aR7bNCOOxe2x80x94 wherein R7a and R7b are independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or heterocyclo. Exemplary preferred R7 substituents include R7aR7bNCOOxe2x80x94 wherein (a) R7a and R7b are each hydrogen, (b) one of R7a and R7b is hydrogen and the other is (i) substituted or unsubstituted C1 to C8 alkyl such as methyl, ethyl, or straight, branched or cyclic propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl such as ethenyl or straight, branched or cyclic propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl such as ethynyl or straight or branched propynyl, butynyl, pentynyl, or hexynyl; (iv) substituted or unsubstituted phenyl, or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl, or (c) R7a and R7b are independently (i) substituted or unsubstituted C1 to C8 alkyl such as methyl, ethyl, or straight, branched or cyclic propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl such as ethenyl or straight, branched or cyclic propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl such as ethynyl or straight or branched propynyl, butynyl, pentynyl, or hexynyl; (iv) substituted or unsubstituted phenyl, or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl. The substituents may be those identified elsewhere herein for substituted hydrocarbyl. In one embodiment, preferred R7 substituents include R7aR7bNCOOxe2x80x94 wherein one of R7a and R7b is hydrogen and the other is methyl, ethyl, or straight, branched or cyclic propyl.
In one of the preferred embodiments, the taxanes of the present invention correspond to structure (2): 
wherein
R7 is carbamoyloxy;
R10 is hydroxy;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, or heterocyclo;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10; and
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
For example, in this preferred embodiment in which the taxane corresponds to structure (2), R7 may be R7aR7bNCOOxe2x80x94 wherein one of R7a and R7b is hydrogen and the other is (i) substituted or unsubstituted C1 to C8 alkyl such as methyl, ethyl, or straight, branched or cyclic propyl, butyl, pentyl, or hexyl; (ii) substituted or unsubstituted C2 to C8 alkenyl such as ethenyl or straight, branched or cyclic propenyl, butenyl, pentenyl or hexenyl; (iii) substituted or unsubstituted C2 to C8 alkynyl such as ethynyl or straight or branched propynyl, butynyl, pentynyl, or hexynyl; (iv) phenyl or substituted phenyl such as nitro, alkoxy or halosubstituted phenyl, or (v) substituted or unsubstituted heteroaromatic such as furyl, thienyl, or pyridyl. The substituents may be those identified elsewhere herein for substituted hydrocarbyl. In one embodiment, preferred R7 substituents include R7aR7bNCOOxe2x80x94 wherein one of R7a and R7b is hydrogen and the other is substituted or unsubstituted, preferably unsubstituted methyl, ethyl, or straight, branched or cyclic propyl. In another embodiment, preferred R7 substituents include R7aR7bNCOOxe2x80x94 wherein one of R7a and R7b is hydrogen and the other is substituted or unsubstituted phenyl or heterocyclo. While R7a and R7b are selected from among these, in one embodiment X3 is selected from substituted or unsubstituted alkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted alkenyl, phenyl or heterocyclo, still more preferably substituted or unsubstituted phenyl or heterocyclo, and still more preferably heterocyclo such as furyl, thienyl or pyridyl. While R7a, R7b, and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl. Alternatively, while R7a, R7b, and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl, or X5 is xe2x80x94COOX10 wherein X10 is alkyl, preferably t-butyl. Among the more preferred embodiments, therefore, are taxanes corresponding to structure (2) in which (i) X5 is xe2x80x94COOX10 wherein X10 is tert-butyl or X5 is xe2x80x94COX10 wherein X10 is phenyl, (ii) X3 is substituted or unsubstituted cycloalkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted isobutenyl, phenyl, furyl, thienyl, or pyridyl, still more preferably unsubstituted isobutenyl, furyl, thienyl or pyridyl, and (iii) R7 is R7aR7bNCOOxe2x80x94, one of R7a and R7b is hydrogen and the other is substituted or unsubstituted C1 to C8 alkyl, phenyl or heterocyclo.
Among the preferred embodiments, therefore, are taxanes corresponding to structure 1 or 2 wherein R7 is R7aR7bNCOOxe2x80x94 wherein R7a is methyl and R7b is hydrido. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
Also among the preferred embodiments are taxanes corresponding to structure 1 or 2 wherein R7 is R7aR7bNCOOxe2x80x94 wherein R7a is ethyl and R7b is hydrido. In this embodiment, X3 is preferably cycloalkyl, isobutenyl, phenyl, substituted phenyl such as p-nitrophenyl, or heterocyclo, more preferably heterocyclo, still more preferably furyl, thienyl or pyridyl; and X5 is preferably benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl. In one alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is keto and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is hydroxy and R14 is hydrido. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydroxy. In another alternative of this embodiment, X3 is heterocyclo; X5 is benzoyl, alkoxycarbonyl, or heterocyclocarbonyl, more preferably benzoyl, t-butoxycarbonyl or t-amyloxycarbonyl, still more preferably t-butoxycarbonyl; R2 is benzoyl, R9 is acyloxy and R14 is hydrido. In each of the alternatives of this embodiment when the taxane has structure 1, R7 and R10 may each have the beta stereochemical configuration, R7 and R10 may each have the alpha stereochemical configuration, R7 may have the alpha stereochemical configuration while R10 has the beta stereochemical configuration or R7 may have the beta stereochemical configuration while R10 has the alpha stereochemical configuration.
C7 Heterosubstituted Acetates
In one embodiment, R7 is R7aC(O)Oxe2x80x94 wherein R7a is heterosubstituted methyl, said heterosubstituted methyl moiety lacking a carbon atom which is in the beta position relative to the carbon atom of which R7a is a substituent. The heterosubstituted methyl is covalently bonded to at least one heteroatom and optionally with hydrogen, the heteroatom being, for example, a nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or halogen atom. The heteroatom may, in turn, be substituted with other atoms to form a heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, oxy, acyloxy, nitro, amino, amido, thiol, ketals, acetals, esters or ether moiety. Exemplary R7 substituents include R7aCOOxe2x80x94 wherein R7a is chloromethyl, hydroxymethyl, methoxymethyl, ethoxymethyl, or methylthiomethyl.
In one of the preferred embodiments, the taxane corresponds to structure 1, X5 is xe2x80x94COX10 wherein X10 is phenyl or xe2x80x94COOX10 wherein X10 is t-butoxycarbonyl, and R7 is R7aC(O)Oxe2x80x94 wherein R7a is alkoxymethyl, preferably methoxymethyl or ethoxymethyl. In another embodiment of the present invention the taxane corresponds to structure 1, X5 is xe2x80x94COX10 wherein X10 is phenyl or xe2x80x94COOX10 wherein X10 is t-butoxycarbonyl, and R7 is R7aC(O)Oxe2x80x94 wherein R7a is acyloxymethyl, preferably acetoxymethyl.
In another embodiment of the present invention, the taxane corresponds to structure 1, X5 is xe2x80x94COX10 wherein X10 is phenyl or xe2x80x94COOX10 wherein X10 is t-butoxycarbonyl, R7 is R7aC(O)Oxe2x80x94 wherein R7a is alkoxymethyl such as methoxymethyl or ethoxymethyl, or aryloxymethyl such as phenoxymethyl, and X3 is heterocyclo. In another embodiment of the present invention the taxane corresponds to structure 1, X5 is xe2x80x94COX10 wherein X10 is phenyl or xe2x80x94COOX10 wherein X10 is t-butoxycarbonyl, and R7 is R7aC(O)Oxe2x80x94 wherein R7a is acyloxymethyl, preferably acetoxymethyl, and X3 is heterocyclo.
In one preferred embodiment, the taxanes of the present invention correspond to structure (2): 
wherein
R7 is heterosubstituted acetate;
R10 is hydroxy;
X3 is substituted or unsubstituted alkyl, alkenyl, alkynyl, or heterocyclo;
X5 is xe2x80x94COX10, xe2x80x94COOX10, or xe2x80x94CONHX10; and
X10 is hydrocarbyl, substituted hydrocarbyl, or heterocyclo.
For example, in this preferred embodiment in which the taxane corresponds to structure (2), R7 may be R7aCOOxe2x80x94 wherein R7a is heterosubstituted methyl, more preferably heterosubstituted methyl wherein the heterosubsituents are selected from the group consisting of nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or halogen atoms, still more preferably heterosubstituted methyl wherein the heterosubstituent is alkoxy or acyloxy. While R7a is selected from among these, in one embodiment X3 is selected from substituted or unsubstituted alkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted alkenyl, phenyl or heterocyclo, still more preferably substituted or unsubstituted phenyl or heterocyclo, and still more preferably heterocyclo such as furyl, thienyl or pyridyl. While R7a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl. Alternatively, while R7a and X3 are selected from among these, in one embodiment X5 is selected from xe2x80x94COX10 wherein X10 is phenyl, alkyl or heterocyclo, more preferably phenyl, or X5 is xe2x80x94COOX10 wherein X10 is alkyl, preferably t-butyl. Among the more preferred embodiments, therefore, are taxanes corresponding to structure (2) in which (i) X5 is xe2x80x94COOX10 wherein X10 is tert-butyl or X5 is xe2x80x94COX10 wherein X10 is phenyl, (ii) X3 is substituted or unsubstituted cycloalkyl, alkenyl, phenyl or heterocyclo, more preferably substituted or unsubstituted isobutenyl, phenyl, furyl, thienyl, or pyridyl, still more preferably unsubstituted isobutenyl, furyl, thienyl or pyridyl, and (iii) R7 is alkoxyacetyl or acyloxyacetyl.
Taxanes having the general formula 1 may be obtained by treatment of a xcex2-lactam with an alkoxide having the taxane tetracyclic nucleus and a C-13 metallic oxide substituent to form compounds having a xcex2-amido ester substituent at C(13), as described more fully in Holton U.S. Pat. No. 5,466,834, followed by removal of the hydroxy protecting groups.
Taxanes having C(10) carbonates may be prepared from 10-deacetylbaccatin III by selective formation of a carbonate of the C-10 hydroxyl group and then protection of the C-7 hydroxyl group (as described more fully in Holton et al., PCT Patent Application WO 99/09021, followed by treatment with a metallic amide. Acylating agents which may be used for the selective acylation of the C(10) hydroxyl group of a taxane include dimethyldicarbonate, diethyldicarbonate, di-t-butyldicarbonate, dibenzyldicarbonate and the like. While the acylation of the C(10) hydroxy group of the taxane will proceed at an adequate rate for many acylating agents, it has been discovered that the reaction rate may be increased by including a Lewis acid in the reaction mixture. Preferred Lewis acids include zinc chloride, stannic chloride, cerium trichloride, cuprous chloride, lanthanum trichloride, dysprosium trichloride, and ytterbium trichloride. Zinc chloride or cerium trichloride is particularly preferred when the acylating agent is a dicarbonate.
Taxanes having C(10) esters may be prepared from 10-deacetylbaccatin III (or a derivative thereof) by selective protection of the C(7) hydroxyl group and then esterification of the C(10) hydroxyl group followed by treatment with a metallic amide. The C(7) hydroxyl group of 10-deacetylbaccatin III, for example, may be selectively protected with a silyl group as described, for example, by Denis, et. al. (J. Am. Chem. Soc., 1988, 110, 5917). In general, the silylating agents may be used either alone or in combination with a catalytic amount of a base such as an alkali metal base.
Taxanes having C(10) carbamates may be prepared from 10-deacetylbaccatin III by protecting the C-7 and C-10 hydroxyl groups of a taxane (as described more fully in Holton et al., PCT Patent Application WO 99/09021), coupling the protected alkoxide with the xcex2-lactam, selectively removing the C(7) and C(10) hydroxy protecting groups, and treating this product with an isocyanate in the presence of a Lewis acid.
Taxanes having C(7) carbonates may be prepared from 10-deacetylbaccatin III (or a derivative thereof) by selective protection of the C-10 hydroxyl group and then acylation of the C-7 hydroxyl group followed by treatment with a metallic amide. The C(10) hydroxyl group of 10-deacetylbaccatin III is then selectively protected with a silyl group using, for example, a silylamide or bissilyamide as a silylating agent. Selective acylation of the C(7) hydroxyl group of a C(10) protected taxane to form a C(7) carbonate can be achieved using any of a variety of common acylating agents such as a haloformates.
Taxanes having C(7) carbamates may be obtained by treatment of a xcex2-lactam with an alkoxide having the taxane tetracyclic nucleus and a C-13 metallic oxide substituent to form compounds having a xcex2-amido ester substituent at C(1 3), as described more fully in Holton U.S. Pat. No. 5,466,834, followed by reaction with an isocyanate or a carbamoyl chloride, and removal of the hydroxy protecting groups.
Taxanes having C(7) esters may be prepared from 10-deacetylbaccatin III (or a derivative thereof) by selective protection of the C-10 hydroxyl group and then esterification of the C-7 hydroxyl group followed by treatment with a metallic amide. The C(10) hydroxyl group of 10-deacetylbaccatin III may be selectively protected with a silyl group using, for example, a silylamide or bissilyamide as a silylating agent. Selective esterification of the C(7) hydroxyl group of a C(10) protected taxane can be achieved using any of a variety of common acylating agents including, but not limited to, substituted and unsubstituted carboxylic acid derivatives, e.g., carboxylic acid halides, anhydrides, dicarbonates, isocyanates and haloformates.
Derivatives of 10-deacetylbaccatin III having alternative substituents at C(2), C(9) and C(14) and processes for their preparation are known in the art. Taxane derivatives having acyloxy substituents other than benzoyloxy at C(2) may be prepared, for example, as described in Holton et al., U.S. Pat. No. 5,728,725 or Kingston et al., U.S. Pat. No. 6,002,023. Taxanes having acyloxy or hydroxy substituents at C(9) in place of keto may be prepared, for example as described in Holton et al., U.S. Pat. No. 6,011,056 or Gunawardana et al., U.S. Pat. No. 5,352,806. Taxanes having a beta hydroxy substituent at C(14) may be prepared from naturally occurring 14-hydroxy-10-deacetylbaccatin III.
Processes for the preparation and resolution of the xcex2-lactam starting material are generally well known. For example, the xcex2-lactam may be prepared as described in Holton, U.S. Pat. No. 5,430,160 and the resulting enatiomeric mixtures of xcex2-lactams may be resolved by a stereoselective hydrolysis using a lipase or enzyme as described, for example, in Patel, U.S. Pat. No. 5,879,929 Patel U.S. Pat. No. 5,567,614 or a liver homogenate as described, for example, in PCT Patent Application No. 00/41204.
Compounds of formula 1 of the instant invention are useful for inhibiting tumor growth in mammals including humans and are preferably administered in the form of a pharmaceutical composition comprising an effective antitumor amount of a compound of the instant invention in combination with at least one pharmaceutically or pharmacologically acceptable carrier. The carrier, also known in the art as an excipient, vehicle, auxiliary, adjuvant, or diluent, is any substance which is pharmaceutically inert, confers a suitable consistency or form to the composition, and does not diminish the therapeutic efficacy of the antitumor compounds. The carrier is xe2x80x9cpharmaceutically or pharmacologically acceptablexe2x80x9d if it does not produce an adverse, allergic or other untoward reaction when administered to a mammal or human, as appropriate.
The pharmaceutical compositions containing the antitumor compounds of the present invention may be formulated in any conventional manner. Proper formulation is dependent upon the route of administration chosen. The compositions of the invention can be formulated for any route of administration so long as the target tissue is available via that route. Suitable routes of administration include, but are not limited to, oral, parenteral (e.g., intravenous, intraarterial, subcutaneous, rectal, subcutaneous, intramuscular, intraorbital, intracapsular, intraspinal, intraperitoneal, or intrasternal), topical (nasal, transdermal, intraocular), intravesical, intrathecal, enteral, pulmonary, intralymphatic, intracavital, vaginal, transurethral, intradermal, aural, intramammary, buccal, orthotopic, intratracheal, intralesional, percutaneous, endoscopical, transmucosal, sublingual and intestinal administration.
Pharmaceutically acceptable carriers for use in the compositions of the present invention are well known to those of ordinary skill in the art and are selected based upon a number of factors: the particular antitumor compound used, and its concentration, stability and intended bioavailability; the disease, disorder or condition being treated with the composition; the subject, its age, size and general condition; and the route of administration. Suitable carriers are readily determined by one of ordinary skill in the art (see, for example, J. G. Nairn, in: Remington""s Pharmaceutical Science (A. Gennaro, ed.), Mack Publishing Co., Easton, Pa., (1985), pp. 1492-1517, the contents of which are incorporated herein by reference).
The compositions are preferably formulated as tablets, dispersible powders, pills, capsules, gelcaps, caplets, gels, liposomes, granules, solutions, suspensions, emulsions, syrups, elixirs, troches, dragees, lozenges, or any other dosage form which can be administered orally. Techniques and compositions for making oral dosage forms useful in the present invention are described in the following references: 7 Modern Pharmaceutics, Chapters 9 and 10 (Banker and Rhodes, Editors, 1979); Lieberman et al., Pharmaceutical Dosage Forms: Tablets (1981); and Ansel, Introduction to Pharmaceutical Dosage Forms 2nd Edition (1976).
The compositions of the invention for oral administration comprise an effective antitumor amount of a compound of the invention in a pharmaceutically acceptable carrier. Suitable carriers for solid dosage forms include sugars, starches, and other conventional substances including lactose, talc, sucrose, gelatin, carboxymethylcellulose, agar, mannitol, sorbitol, calcium phosphate, calcium carbonate, sodium carbonate, kaolin, alginic acid, acacia, corn starch, potato starch, sodium saccharin, magnesium carbonate, tragacanth, microcrystalline cellulose, colloidal silicon dioxide, croscarmellose sodium, talc, magnesium stearate, and stearic acid. Further, such solid dosage forms may be uncoated or may be coated by known techniques; e.g., to delay disintegration and absorption.
The antitumor compounds of the present invention are also preferably formulated for parenteral administration, e.g., formulated for injection via intravenous, intraarterial, subcutaneous, rectal, subcutaneous, intramuscular, intraorbital, intracapsular, intraspinal, intraperitoneal, or intrasternal routes. The compositions of the invention for parenteral administration comprise an effective antitumor amount of the antitumor compound in a pharmaceutically acceptable carrier. Dosage forms suitable for parenteral administration include solutions, suspensions, dispersions, emulsions or any other dosage form which can be administered parenterally. Techniques and compositions for making parenteral dosage forms are known in the art.
Suitable carriers used in formulating liquid dosage forms for oral or parenteral administration include nonaqueous, pharmaceutically-acceptable polar solvents such as oils, alcohols, amides, esters, ethers, ketones, hydrocarbons and mixtures thereof, as well as water, saline solutions, dextrose solutions (e.g., DW5), electrolyte solutions, or any other aqueous, pharmaceutically acceptable liquid.
Suitable nonaqueous, pharmaceutically-acceptable polar solvents include, but are not limited to, alcohols (e.g., xcex1-glycerol formal, xcex2-glycerol formal, 1,3-butyleneglycol, aliphatic or aromatic alcohols having 2-30 carbon atoms such as methanol, ethanol, propanol, isopropanol, butanol, t-butanol, hexanol, octanol, amylene hydrate, benzyl alcohol, glycerin (glycerol), glycol, hexylene glycol, tetrahydrofurfuryl alcohol, lauryl alcohol, cetyl alcohol, or stearyl alcohol, fatty acid esters of fatty alcohols such as polyalkylene glycols (e.g., polypropylene glycol, polyethylene glycol), sorbitan, sucrose and cholesterol); amides (e.g., dimethylacetamide (DMA), benzyl benzoate DMA, dimethylformamide, N-(xcex2-hydroxyethyl)-lactamide, N, N-dimethylacetamide amides, 2-pyrrolidinone, 1-methyl-2-pyrrolidinone, or polyvinylpyrrolidone); esters (e.g., 1-methyl-2-pyrrolidinone, 2-pyrrolidinone, acetate esters such as monoacetin, diacetin, and triacetin, aliphatic or aromatic esters such as ethyl caprylate or octanoate, alkyl oleate, benzyl benzoate, benzyl acetate, dimethylsulfoxide (DMSO), esters of glycerin such as mono, di, or tri-glyceryl citrates or tartrates, ethyl benzoate, ethyl acetate, ethyl carbonate, ethyl lactate, ethyl oleate, fatty acid esters of sorbitan, fatty acid derived PEG esters, glyceryl monostearate, glyceride esters such as mono, di, or tri-glycerides, fatty acid esters such as isopropyl myristrate, fatty acid derived PEG esters such as PEG-hydroxyoleate and PEG-hydroxystearate, N-methyl pyrrolidinone, pluronic 60, polyoxyethylene sorbitol oleic polyesters such as poly(ethoxylated)30-60 sorbitol poly(oleate)2-4, poly(oxyethylene)15-20 monooleate, poly(oxyethylene)15-20 mono 12-hydroxystearate, and poly(oxyethylene)15-20 mono ricinoleate, polyoxyethylene sorbitan esters such as polyoxyethylene-sorbitan monooleate, polyoxyethylene-sorbitan monopalmitate, polyoxyethylene-sorbitan monolaurate, polyoxyethylene-sorbitan monostearate, and Polysorbate(copyright) 20, 40, 60 or 80 from ICI Americas, Wilmington, Del., polyvinylpyrrolidone, alkyleneoxy modified fatty acid esters such as polyoxyl 40 hydrogenated castor oil and polyoxyethylated castor oils (e.g., Cremophor(copyright) EL solution or Cremophor(copyright) RH 40 solution), saccharide fatty acid esters (i.e., the condensation product of a monosaccharide (e.g., pentoses such as ribose, ribulose, arabinose, xylose, lyxose and xylulose, hexoses such as glucose, fructose, galactose, mannose and sorbose, trioses, tetroses, heptoses, and octoses), disaccharide (e.g., sucrose, maltose, lactose and trehalose) or oligosaccharide or mixture thereof with a C4-C22 fatty acid(s)(e.g., saturated fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid and stearic acid, and unsaturated fatty acids such as palmitoleic acid, oleic acid, elaidic acid, erucic acid and linoleic acid)), or steroidal esters); alkyl, aryl, or cyclic ethers having 2-30 carbon atoms (e.g., diethyl ether, tetrahydrofuran, dimethyl isosorbide, diethylene glycol monoethyl ether); glycofurol (tetrahydrofurfuryl alcohol polyethylene glycol ether); ketones having 3-30 carbon atoms (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone); aliphatic, cycloaliphatic or aromatic hydrocarbons having 4-30 carbon atoms (e.g., benzene, cyclohexane, dichloromethane, dioxolanes, hexane, n-decane, n-dodecane, n-hexane, sulfolane, tetramethylenesulfon, tetramethylenesulfoxide, toluene, dimethylsulfoxide (DMSO), or tetramethylenesulfoxide); oils of mineral, vegetable, animal, essential or synthetic origin (e.g., mineral oils such as aliphatic or wax-based hydrocarbons, aromatic hydrocarbons, mixed aliphatic and aromatic based hydrocarbons, and refined paraffin oil, vegetable oils such as linseed, tung, safflower, soybean, castor, cottonseed, groundnut, rapeseed, coconut, palm, olive, corn, corn germ, sesame, persic and peanut oil and glycerides such as mono-, di- or triglycerides, animal oils such as fish, marine, sperm, cod-liver, haliver, squalene, squalane, and shark liver oil, oleic oils, and polyoxyethylated castor oil); alkyl or aryl halides having 1-30 carbon atoms and optionally more than one halogen substituent; methylene chloride; monoethanolamine; petroleum benzin; trolamine; omega-3 polyunsaturated fatty acids (e.g., alpha-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, or docosahexaenoic acid); polyglycol ester of 12-hydroxystearic acid and polyethylene glycol (Solutol(copyright) HS-15, from BASF, Ludwigshafen, Germany); polyoxyethylene glycerol; sodium laurate; sodium oleate; or sorbitan monooleate.
Other pharmaceutically acceptable solvents for use in the invention are well known to those of ordinary skill in the art, and are identified in The Chemotherapy Source Book (Williams and Wilkens Publishing), The Handbook of Pharmaceutical Excipients, (American Pharmaceutical Association, Washington, D.C., and The Pharmaceutical Society of Great Britain, London, England, 1968), Modern Pharmaceutics, (G. Banker et al., eds., 3d ed.)(Marcel Dekker, Inc., New York, N.Y., 1995), The Pharmacological Basis of Therapeutics, (Goodman and Gilman, McGraw Hill Publishing), Pharmaceutical Dosage Forms, (H. Lieberman et al., eds., )(Marcel Dekker, Inc., New York, N.Y., 1980), Remington""s Pharmaceutical Sciences (A. Gennaro, ed., 19th ed.)(Mack Publishing, Easton, Pa., 1995), The United States Pharmacopeia 24, The National Formulary 19, (National Publishing, Philadelphia, Pa., 2000), A. J. Spiegel et al., and Use of Nonaqueous Solvents in Parenteral Products, JOURNAL OF PHARMACEUTICAL SCIENCES, Vol. 52, No.10, pp. 917-927 (1963).
Preferred solvents include those known to stabilize the antitumor compounds, such as oils rich in triglycerides, for example, safflower oil, soybean oil or mixtures thereof, and alkyleneoxy modified fatty acid esters such as polyoxyl 40 hydrogenated castor oil and polyoxyethylated castor oils (e.g., Cremophor(copyright) EL solution or Cremophor(copyright) RH 40 solution). Commercially available triglycerides include Intralipid(copyright) emulsified soybean oil (Kabi-Pharmacia Inc., Stockholm, Sweden), Nutralipid (copyright) emulsion (McGaw, Irvine, Calif.), Liposyn(copyright) II 20% emulsion (a 20% fat emulsion solution containing 100 mg safflower oil, 100 mg soybean oil, 12 mg egg phosphatides, and 25 mg glycerin per ml of solution; Abbott Laboratories, Chicago, Ill.), Liposyn((copyright) III 2% emulsion (a 2% fat emulsion solution containing 100 mg safflower oil, 100 mg soybean oil, 12 mg egg phosphatides, and 25 mg glycerin per ml of solution; Abbott Laboratories, Chicago, Ill.), natural or synthetic glycerol derivatives containing the docosahexaenoyl group at levels between 25% and 100% by weight based on the total fatty acid content (Dhasco(copyright) (from Martek Biosciences Corp., Columbia, Md.), DHA Maguro(copyright) (from Daito Enterprises, Los Angeles, Calif.), Soyacal(copyright), and Travemulsion(copyright). Ethanol is a preferred solvent for use in dissolving the antitumor compound to form solutions, emulsions, and the like.
Additional minor components can be included in the compositions of the invention for a variety of purposes well known in the pharmaceutical industry. These components will for the most part impart properties which enhance retention of the antitumor compound at the site of administration, protect the stability of the composition, control the pH, facilitate processing of the antitumor compound into pharmaceutical formulations, and the like. Preferably, each of these components is individually present in less than about 15 weight % of the total composition, more preferably less than about 5 weight %, and most preferably less than about 0.5 weight % of the total composition. Some components, such as fillers or diluents, can constitute up to 90 wt. % of the total composition, as is well known in the formulation art. Such additives include cryoprotective agents for preventing reprecipitation of the taxane, surface active, wetting or emulsifying agents (e.g., lecithin, polysorbate-80, Tween(copyright) 80, pluronic 60, polyoxyethylene stearate ), preservatives (e.g., ethyl-p-hydroxybenzoate), microbial preservatives (e.g., benzyl alcohol, phenol, m-cresol, chlorobutanol, sorbic acid, thimerosal and paraben), agents for adjusting pH or buffering agents (e.g., acids, bases, sodium acetate, sorbitan monolaurate), agents for adjusting osmolarity (e.g., glycerin), thickeners (e.g., aluminum monostearate, stearic acid, cetyl alcohol, stearyl alcohol, guar gum, methyl cellulose, hydroxypropylcellulose, tristearin, cetyl wax esters, polyethylene glycol), colorants, dyes, flow aids, non-volatile silicones (e.g., cyclomethicone), clays (e.g., bentonites), adhesives, bulking agents, flavorings, sweeteners, adsorbents, fillers (e.g., sugars such as lactose, sucrose, mannitol, or sorbitol, cellulose, or calcium phosphate), diluents (e.g., water, saline, electrolyte solutions), binders (e.g., starches such as maize starch, wheat starch, rice starch, or potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropyl methylcellulose, sodium carboxymethyl cellulose, polyvinylpyrrolidone, sugars, polymers, acacia), disintegrating agents (e.g., starches such as maize starch, wheat starch, rice starch, potato starch, or carboxymethyl starch, cross-linked polyvinyl pyrrolidone, agar, alginic acid or a salt thereof such as sodium alginate, croscarmellose sodium or crospovidone), lubricants (e.g., silica, talc, stearic acid or salts thereof such as magnesium stearate, or polyethylene glycol), coating agents (e.g., concentrated sugar solutions including gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol, or titanium dioxide), and antioxidants (e.g., sodium metabisulfite, sodium bisulfite, sodium sulfite, dextrose, phenols, and thiophenols).
In a preferred embodiment, a pharmaceutical composition of the invention comprises at least one nonaqueous, pharmaceutically acceptable solvent and an antitumor compound having a solubility in ethanol of at least about 100, 200, 300, 400, 500, 600, 700 or 800 mg/ml. While not being bound to a particular theory, it is believed that the ethanol solubility of the antitumor compound may be directly related to its efficacy. The antitumor compound can also be capable of being crystallized from a solution. In other words, a crystalline antitumor compound, such as compound 1393, can be dissolved in a solvent to form a solution and then recrystallized upon evaporation of the solvent without the formation of any amorphous antitumor compound. It is also preferred that the antitumor compound have an ID50 value (i.e, the drug concentration producing 50% inhibition of colony formation) of at least 4, 5, 6, 7, 8, 9, or 10 times less that of paclitaxel when measured according to the protocol set forth in the working examples.
Dosage form administration by these routes may be continuous or intermittent, depending, for example, upon the patient""s physiological condition, whether the purpose of the administration is therapeutic or prophylactic, and other factors known to and assessable by a skilled practitioner.
Dosage and regimens for the administration of the pharmaceutical compositions of the invention can be readily determined by those with ordinary skill in treating cancer. It is understood that the dosage of the antitumor compounds will be dependent upon the age, sex, health, and weight of the recipient, kind of concurrent treatment, if any, frequency of treatment, and the nature of the effect desired. For any mode of administration, the actual amount of antitumor compound delivered, as well as the dosing schedule necessary to achieve the advantageous effects described herein, will also depend, in part, on such factors as the bioavailability of the antitumor compound, the disorder being treated, the desired therapeutic dose, and other factors that will be apparent to those of skill in the art. The dose administered to an animal, particularly a human, in the context of the present invention should be sufficient to effect the desired therapeutic response in the animal over a reasonable period of time. Preferably, an effective amount of the antitumor compound, whether administered orally or by another route, is any amount which would result in a desired therapeutic response when administered by that route. Preferably, the compositions for oral administration are prepared in such a way that a single dose in one or more oral preparations contains at least 20 mg of the antitumor compound per m2 of patient body surface area, or at least 50, 100, 150, 200, 300, 400, or 500 mg of the antitumor compound per m2 of patient body surface area, wherein the average body surface area for a human is 1.8 m2. Preferably, a single dose of a composition for oral administration contains from about 20 to about 600 mg of the antitumor compound per m2 of patient body surface area, more preferably from about 25 to about 400 mg/m2 even more preferably, from about 40 to about 300 mg/m2, and even more preferably from about 50 to about 200 mg/m2. Preferably, the compositions for parenteral administration are prepared in such a way that a single dose contains at least 20 mg of the antitumor compound per m2 of patient body surface area, or at least 40, 50, 100, 150, 200, 300, 400, or 500 mg of the antitumor compound per m2 of patient body surface area. Preferably, a single dose in one or more parenteral preparations contains from about 20 to about 500 mg of the antitumor compound per m2 of patient body surface area, more preferably from about 40 to about 400 mg/m2 and even more preferably, from about 60 to about 350 mg/m2. However, the dosage may vary depending on the dosing schedule which can be adjusted as necessary to achieve the desired therapeutic effect. It should be noted that the ranges of effective doses provided herein are not intended to limit the invention and represent preferred dose ranges. The most preferred dosage will be tailored to the individual subject, as is understood and determinable by one of ordinary skill in the art without undue experimentation.
The concentration of the antitumor compound in a liquid pharmaceutical composition is preferably between about 0.01 mg and about 10 mg per ml of the composition, more preferably between about 0.1 mg and about 7 mg per ml, even more preferably between about 0.5 mg and about 5 mg per ml, and most preferably between about 1.5 mg and about 4 mg per ml. Relatively low concentrations are generally preferred because the antitumor compound is most soluble in the solution at low concentrations. The concentration of the antitumor compound in a solid pharmaceutical composition for oral administration is preferably between about 5 weight % and about 50 weight %, based on the total weight of the composition, more preferably between about 8 weight % and about 40 weight %, and most preferably between about 10 weight % and about 30 weight %.
In one embodiment, solutions for oral administration are prepared by dissolving an antitumor compound in any pharmaceutically acceptable solvent capable of dissolving the compound (e.g., ethanol or methylene chloride) to form a solution. An appropriate volume of a carrier which is a solution, such as Cremophor(copyright) EL solution, is added to the solution while stirring to form a pharmaceutically acceptable solution for oral administration to a patient. If desired, such solutions can be formulated to contain a minimal amount of, or to be free of, ethanol, which is known in the art to cause adverse physiological effects when administered at certain concentrations in oral formulations.
In another embodiment, powders or tablets for oral administration are prepared by dissolving an antitumor compound in any pharmaceutically acceptable solvent capable of dissolving the compound (e.g.,ethanol or methylene chloride) to form a solution. The solvent can optionally be capable of evaporating when the solution is dried under vacuum. An additional carrier can be added to the solution prior to drying, such as Cremophor(copyright) EL solution. The resulting solution is dried under vacuum to form a glass. The glass is then mixed with a binder to form a powder. The powder can be mixed with fillers or other conventional tabletting agents and processed to form a tablet for oral administration to a patient. The powder can also be added to any liquid carrier as described above to form a solution, emulsion, suspension or the like for oral administration.
Emulsions for parenteral administration can be prepared by dissolving an antitumor compound in any pharmaceutically acceptable solvent capable of dissolving the compound (e.g., ethanol or methylene chloride) to form a solution. An appropriate volume of a carrier which is an emulsion, such as Liposyn(copyright) II or Liposyn(copyright) III emulsion, is added to the solution while stirring to form a pharmaceutically acceptable emulsion for parenteral administration to a patient. If desired, such emulsions can be formulated to contain a minimal amount of, or to be free of, ethanol or Cremophor(copyright) solution, which are known in the art to cause adverse physiological effects when administered at certain concentrations in parenteral formulations.
Solutions for parenteral administration can be prepared by dissolving an antitumor compound in any pharmaceutically acceptable solvent capable of dissolving the compound (e.g., ethanol or methylene chloride) to form a solution. An appropriate volume of a carrier which is a solution, such as Cremophor(copyright) solution, is added to the solution while stirring to form a pharmaceutically acceptable solution for parenteral administration to a patient. If desired, such solutions can be formulated to contain a minimal amount of, or to be free of, ethanol or Cremophor(copyright) solution, which are known in the art to cause adverse physiological effects when administered at certain concentrations in parenteral formulations.
If desired, the emulsions or solutions described above for oral or parenteral administration can be packaged in IV bags, vials or other conventional containers in concentrated form and diluted with any pharmaceutically acceptable liquid, such as saline, to form an acceptable taxane concentration prior to use as is known in the art.
Definitions The terms xe2x80x9chydrocarbonxe2x80x9d and xe2x80x9chydrocarbylxe2x80x9d as used herein describe organic compounds or radicals consisting exclusively of the elements carbon and hydrogen. These moieties include alkyl, alkenyl, alkynyl, and aryl moieties. These moieties also include alkyl, alkenyl, alkynyl, and aryl moieties substituted with other aliphatic or cyclic hydrocarbon groups, such as alkaryl, alkenaryl and alkynaryl. Unless otherwise indicated, these moieties preferably comprise 1 to 20 carbon atoms.
The xe2x80x9csubstituted hydrocarbylxe2x80x9d moieties described herein are hydrocarbyl moieties which are substituted with at least one atom other than carbon, including moieties in which a carbon chain atom is substituted with a hetero atom such as nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or a halogen atom. These substituents include halogen, heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, keto, acyl, acyloxy, nitro, amino, amido, nitro, cyano, thiol, ketals, acetals, esters and ethers.
The term xe2x80x9cheteroatomxe2x80x9d shall mean atoms other than carbon and hydrogen.
The xe2x80x9cheterosubstituted methylxe2x80x9d moieties described herein are methyl groups in which the carbon atom is covalently bonded to at least one heteroatom and optionally with hydrogen, the heteroatom being, for example, a nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or halogen atom. The heteroatom may, in turn, be substituted with other atoms to form a heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, oxy, acyloxy, nitro, amino, amido, thiol, ketals, acetals, esters or ether moiety.
The xe2x80x9cheterosubstituted acetatexe2x80x9d moieties described herein are acetate groups in which the carbon of the methyl group is covalently bonded to at least one heteroatom and optionally with hydrogen, the heteroatom being, for example, a nitrogen, oxygen, silicon, phosphorous, boron, sulfur, or halogen atom. The heteroatom may, in turn, be substituted with other atoms to form a heterocyclo, alkoxy, alkenoxy, alkynoxy, aryloxy, hydroxy, protected hydroxy, oxy, acyloxy, nitro, amino, amido, thiol, ketals, acetals, esters or ether moiety.
Unless otherwise indicated, the alkyl groups described herein are preferably lower alkyl containing from one to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain or cyclic and include methyl, ethyl, propyl, isopropyl, butyl, hexyl and the like.
Unless otherwise indicated, the alkenyl groups described herein are preferably lower alkenyl containing from two to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain or cyclic and include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, hexenyl, and the like.
Unless otherwise indicated, the alkynyl groups described herein are preferably lower alkynyl containing from two to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain and include ethynyl, propynyl, butynyl, isobutynyl, hexynyl, and the like.
The terms xe2x80x9carylxe2x80x9d or xe2x80x9carxe2x80x9d as used herein alone or as part of another group denote optionally substituted homocyclic aromatic groups, preferably monocyclic or bicyclic groups containing from 6 to 12 carbons in the ring portion, such as phenyl, biphenyl, naphthyl, substituted phenyl, substituted biphenyl or substituted naphthyl. Phenyl and substituted phenyl are the more preferred aryl.
The terms xe2x80x9chalogenxe2x80x9d or xe2x80x9chaloxe2x80x9d as used herein alone or as part of another group refer to chlorine, bromine, fluorine, and iodine.
The terms xe2x80x9cheterocycloxe2x80x9d or xe2x80x9cheterocyclicxe2x80x9d as used herein alone or as part of another group denote optionally substituted, fully saturated or unsaturated, monocyclic or bicyclic, aromatic or nonaromatic groups having at least one heteroatom in at least one ring, and preferably 5 or 6 atoms in each ring. The heterocyclo group preferably has 1 or 2 oxygen atoms, 1 or 2 sulfur atoms, and/or 1 to 4 nitrogen atoms in the ring, and may be bonded to the remainder of the molecule through a carbon or heteroatom. Exemplary heterocyclo include heteroaromatics such as furyl, thienyl, pyridyl, oxazolyl, pyrrolyl, indolyl, quinolinyl, or isoquinolinyl and the like. Exemplary substituents include one or more of the following groups: hydrocarbyl, substituted hydrocarbyl, keto, hydroxy, protected hydroxy, acyl, acyloxy, alkoxy, alkenoxy, alkynoxy, aryloxy, halogen, amido, amino, nitro, cyano, thiol, ketals, acetals, esters and ethers.
The term xe2x80x9cheteroaromaticxe2x80x9d as used herein alone or as part of another group denote optionally substituted aromatic groups having at least one heteroatom in at least one ring, and preferably 5 or 6 atoms in each ring. The heteroaromatic group preferably has 1 or 2 oxygen atoms, 1 or 2 sulfur atoms, and/or 1 to 4 nitrogen atoms in the ring, and may be bonded to the remainder of the molecule through a carbon or heteroatom. Exemplary heteroaromatics include furyl, thienyl, pyridyl, oxazolyl, pyrrolyl, indolyl, quinolinyl, or isoquinolinyl and the like. Exemplary substituents include one or more of the following groups: hydrocarbyl, substituted hydrocarbyl, keto, hydroxy, protected hydroxy, acyl, acyloxy, alkoxy, alkenoxy, alkynoxy, aryloxy, halogen, amido, amino, nitro, cyano, thiol, ketals, acetals, esters and ethers.
The term xe2x80x9cacyl,xe2x80x9d as used herein alone or as part of another group, denotes the moiety formed by removal of the hydroxyl group from the group xe2x80x94COOH of an organic carboxylic acid, e.g., RC(O)xe2x80x94, wherein R is R1, R1Oxe2x80x94, R1R2Nxe2x80x94, or R1Sxe2x80x94, R1 is hydrocarbyl, heterosubstituted hydrocarbyl, or heterocyclo and R2 is hydrogen, hydrocarbyl or substituted hydrocarbyl.
The term xe2x80x9cacyloxy,xe2x80x9d as used herein alone or as part of another group, denotes an acyl group as described above bonded through an oxygen linkage (xe2x80x94Oxe2x80x94), e.g., RC(O)Oxe2x80x94 wherein R is as defined in connection with the term xe2x80x9cacyl.xe2x80x9d
Unless otherwise indicated, the alkoxycarbonyloxy moieties described herein comprise lower hydrocarbon or substituted hydrocarbon or substituted hydrocarbon moieties.
Unless otherwise indicated, the carbamoyloxy moieties described herein are derivatives of carbamic acid in which one or both of the amine hydrogens is optionally replaced by a hydrocarbyl, substituted hydrocarbyl or heterocyclo moiety.
The terms xe2x80x9chydroxyl protecting groupxe2x80x9d and xe2x80x9chydroxy protecting groupxe2x80x9d as used herein denote a group capable of protecting a free hydroxyl group (xe2x80x9cprotected hydroxylxe2x80x9d) which, subsequent to the reaction for which protection is employed, may be removed without disturbing the remainder of the molecule. A variety of protecting groups for the hydroxyl group and the synthesis thereof may be found in xe2x80x9cProtective Groups in Organic Synthesisxe2x80x9d by T. W. Greene, John Wiley and Sons, 1981, or Fieser and Fieser. Exemplary hydroxyl protecting groups include methoxymethyl, 1-ethoxyethyl, benzyloxymethyl, (.beta.-trimethylsilylethoxy)methyl, tetrahydropyranyl, 2,2,2-trichloroethoxycarbonyl, t-butyl(diphenyl)silyl, trialkylsilyl, trichloromethoxycarbonyl and 2,2,2-trichloroethoxymethyl.
As used herein, xe2x80x9cAcxe2x80x9d means acetyl; xe2x80x9cBzxe2x80x9d means benzoyl; xe2x80x9cEtxe2x80x9d means ethyl; xe2x80x9cMexe2x80x9d means methyl; xe2x80x9cPhxe2x80x9d means phenyl; xe2x80x9cPrxe2x80x9d means propyl; xe2x80x9ciPrxe2x80x9d means isopropyl; xe2x80x9cBuxe2x80x9d means butyl; xe2x80x9cAmxe2x80x9d means amyl; xe2x80x9cCproxe2x80x9d means cyclopropyl; xe2x80x9ctBuxe2x80x9d and xe2x80x9ct-Buxe2x80x9d means tert-butyl; xe2x80x9cRxe2x80x9d means lower alkyl unless otherwise defined; xe2x80x9cPyxe2x80x9d means pyridine or pyridyl; xe2x80x9cTESxe2x80x9d means triethylsilyl; xe2x80x9cTMSxe2x80x9d means trimethylsilyl; xe2x80x9cLAHxe2x80x9d means lithium aluminum hydride; xe2x80x9c10-DABxe2x80x9d means 10-desacetylbaccatin IIIxe2x80x9d; xe2x80x9camine protecting groupxe2x80x9d includes, but is not limited to, carbamates, for example, 2,2,2-trichloroethylcarbamate or tertbutylcarbamate; xe2x80x9cprotected hydroxyxe2x80x9d means xe2x80x94OP wherein P is a hydroxy protecting group; xe2x80x9cPhCOxe2x80x9d means phenylcarbonyl; xe2x80x9ctBuOCOxe2x80x9d and xe2x80x9cBocxe2x80x9d mean tert-butoxycarbonyl; xe2x80x9ctAmOCOxe2x80x9d means tert-amyloxycarbonyl; xe2x80x9c2-FuCOxe2x80x9d means 2-furylcarbonyl; xe2x80x9c2-ThCOxe2x80x9d means 2-thienylcarbonyl; xe2x80x9c2-PyCOxe2x80x9d means 2-pyridylcarbonyl; xe2x80x9c3-PyCOxe2x80x9d means 3-pyridylcarbonyl; xe2x80x9c4-PyCOxe2x80x9d means 4-pyridylcarbonyl; xe2x80x9cC4H7COxe2x80x9d means butenylcarbonyl; xe2x80x9ctC3H5COxe2x80x9d means trans-propenylcarbonyl; xe2x80x9cEtOCOxe2x80x9d means ethoxycarbonyl; xe2x80x9cibueCOxe2x80x9d means isobutenylcarbonyl; xe2x80x9ciBuCOxe2x80x9d means isobutylcarbonyl; xe2x80x9ciBuOCOxe2x80x9d means isobutoxycarbonyl; xe2x80x9ciPrOCOxe2x80x9d means isopropyloxycarbonyl; xe2x80x9cnPrOCOxe2x80x9d means n-propyloxycarbonyl; xe2x80x9cnPrCOxe2x80x9d means n-propylcarbonyl; xe2x80x9cibuexe2x80x9d means isobutenyl; xe2x80x9cTHFxe2x80x9d means tetrahydrofuran; xe2x80x9cDMAPxe2x80x9d means 4-dimethylamino pyridine; xe2x80x9cLHMDSxe2x80x9d means Lithium HexamethylDiSilazanide.
The term xe2x80x9cstorage stable compositionxe2x80x9d as used herein is a composition which, after storage at room temperature for one year and dilution prior to use, is suitable for administration to a patient and is cytotoxically active.